Closed thermal system



7 2 Sheeis-Sheet 1 E. S. CORNELL. JR

l asi CLOSED THERMAL SYSTEM Original Filed Oct. 28', 1937.

.H' ORNEY INVENTOR Ed r0 scornelLJrt 1940- E. s. CORNELL, JR v 2,220,078

CLOSED THERMAL SYSTEM Original Filed Oct. 28, 1937 -2 Sheets-Sheet 2INVENTOR m FORNEY E: card 5. ?,Jr} Y 2 e-w Patented Nov. 5, 1940 UNITEDSTATES PATENT OFFICE 2,220,078 CLOSED THERMAL (SYSTEM I Edward S.Cornell, Jr., Larchmont, N. Y.

Application October 28, 1937, Serial No. 171,539 Renewed February 7,1940 6 Claims.

This invention relates to improvements in' heating systems.

More particularly, this invention relates to improvements in heatingsystems embodying the circulation of a suitably treated thermal medium,such as heated water, through a closed piping system including one ormore heat exchange units. The system may be of the pressure type, inwhich the pressure of expansion of the 10 thermal medium, on heating, ispermitted to increase to a previously established degree, whereuponmeans are provided to relieve the system, as by discharge of thermalmedium therefrom, to prevent the creation of dangerous pressures. The 15heating system may be adapted to include an auxiliary system, such as asystem supplying hot water for domestic use.

It is a feature of this invention that the circulation system isprovided with surgeand shockabsorbent means comprising a cushioningchamber of air or other gas, said means forming a unit of the pipingsystem. The free surface of such gas cushion is at all times in directcontact with the circulating thermal fluid in the closing 25 pipingcircuit, and the area of such surface, during the range of operation ofthe system is preferably equivalent to or greater than the area of themain feed pipe of the piping system.

The invention further provides for the restric 30 tion,inc1usive ofabsolute preclusion, of circulation of thermal fluid through the heatexchangers forming the main system, said means including a valvestructure normally arranged to permit water circulation through thesystem only in the circumstanceof a suitable velocity head Within thesystem. 7

Advantageously, such velocity head may be generated by-positive pumpingmeans, such for example as the Water circulator set forth and absorbentmeans functions in full cooperation 55 with the circulation of thethermal medium through the auxiliary heat exchange system, which remainsin full operative status.

In this invention, the stated flow control valve means and cushion meansmay be embodied in a 50 preferably unitary structure. The gasentrapclaimed in my presently co-pending application crease iscompensated for by a contraction of volment chamber is preferablydisposed anteriorly of the flow valve, and arranged to provide acushioning volume of air ata point communicating with the main flow lineof the closed piping system, said air cushion preferably having a freesurface equal to or greater than the area of the main feed pipe servingthe piping system. It is a feature of the invention that surges of waterwithin the system, and sound-wave vibrations generated within andcarried by the water stream of the system are thus directly interceptedby a cushioning surface of great effective area, disposed directly inthe path of water flow.

It-has been found that an air cushion having a relatively small volumebut large free surface functions eflicient'ly to absorb surges or shockswithin the system, and it is thus a characteristic of the invention thatonly a part of the air, steam, vapor or other gas normally liberate-dfrom the water during and incident to the initial filling of the systemor subsequent additions of water thereto, and during the stage ofheating the water within the system is retained for cushioning purposes.The air chamber comprising the cushioning means may therefore be ofcomparatively small volumetric content, the stated volume bearing apredetermined relationship to the size of the main in which it isinstalled. In initiating the operation of the system, therefore, stepsare taken to drive a greater 3o portion of the normally occluded air orother gas into the radiators or other heat exchange units of the mainthermal system, whence it may be removed by manipulation of the usualair-vent cocks. Advantageously an auxiliary air-receiver may beconnected, as by piping, to the air-cushion chamber, the totalvolumetric content of the chamber, the auxiliary receiver and the pipingconnected therewith, being such that the free surface of the entrappedair or gas is directly exposed to the fluid in to system, and of theproper area. The use of such auxiliary receiver enables theestabllshment of minimum dimensions for the cushioning unit, and alsomakes the system readily adaptable to abnormal operating conditions.

The, air entrapment chamber may be provided with air release means and agage glass, so that the volumetric contentof the air cushion may bedefinitely established.

It is well known that in a closed pipingsystem, an increase in thetemperature of the fluid therein effects a corresponding pressureincrease within the system. Initially, the stated pressure inume of theair cushion. Such pressure increase and air cushion contraction may bepermitted to continue until a predetermined pressure has been attained,whereupon suitable mechanical pressure relief means, such as thecombined presa sure relief and discharge valve set forth and claimed inmy presentlyco-pending application, Serial No. 171,540, dated October28th, 1937, may function to control the pressure by suitable dischargeof the thermal fluid.

Advantageously, a pressure reducing valve may be interposed between theexternal source of thermal medium, such as the customary water supply,and the boiler. Such pressure reducing valve therby serves as anautomatic boiler feed, in that when the pressure within the system dropsto a point below the setting of the pressure reducing valve, suchpressure reduction usually being occasioned by an excessivepressure-relief valve discharge from the boiler and subsequent reductionin temperature, water will be admitted from the water supply to theboiler until the pressure within the system equals the set point of. thepressure reducing valve. Y

, Other features and advantages hereinafter appear.

In the accompanying drawings:

' Fig. 1 illustrates a closed thermal heating system, installed pursuantto the principles of the invention;

Fig. 2 is a vertical sectional view of one embodiment of the combinedflow-control valve and air cushion means employed in the heating systemof Fig. 1; and V Fig. 3 is a plan view of the structure of Fig. 2.

Referring to-Figure 1, the heating system includes a central heatingsource, such as the heating boiler l0, which heats water or othersuitable thermal fluid for circulation through one or more supply mainsl2 and return mains I4, in a closed piping system. As required along therun of the supply main or mains, one or more risers iii are suitablyconnected, respectively leading to the one or more heat exchange units[1. Return lines 20, connect the respective heat exchangers with thereturn main H. The heat exchange units 1 'Las illustrated,may be of thetype disclosed in my United States Patent No. 2,038,347, dated April 21,1936, and entitled Air conditioned heating and cooling system, in whichcompressed air, preferably preconditioned, serves to actuate fan means,or equivalent, for effecting the circulation of the air of the room orother space served by the respective exchange units and to addincrements of conditioned air, inclusive of increments of fresh air, andto thermally treat the'air of such room or other space. It is apparentthat conventional heat exchange units, such as the common heatingradiators may be employed in connection with the invention, and that therepresentation in Fig. 1 oftwo heat exchange units H, H, typifies anysuitable thermal system employing any desired number of heat exchangeunits.

To effect a positive circulation of the thermal fluid through thesystem, there is preferably employed a circulator 23, advantageouslylocated in a return line ll. Such circulator may be any conventionalfluid-circulating pump; preferably, however, it is the improvedcirculator set forth and claimed in my co-pending application previouslyreferred to.

A thermostat 24, of conventional design, may be installed in anyselected room or other space served by a. heating unit, II, the make andbreak switch mechanism of said thermostat controlling the electriccircuit 2! of the circulator 23 and thus operating as a thermallyresponsive switch to start and stop the circulator motor in accordancewith room temperature condition.

vWater may be initially supplied to the boiler In through the supplypipe 26, in which may be located a manually operable shut-off valve 28,a pressure reducing valve 30 and a pressure, relief valve 32, theseunits preferably being assembled in the order named and as illustrated.The water feed 26a to the boiler Ill may enter the boiler through asuitable Tin return main l4, as shown.

As ls'well understood, an increase in pressure of a closed thermal-fluidcirculating system results from increasing temperatures therein. Toprevent the creation of excess pressures within the system, it is commonpractice to employ a pressure relief valve, .as is indicated at 32, todischarge fluid through a suitably piped discharge line 33, such reliefvalve being set to discharge at a predetermined pressure.

It will be obvious that after a discharge of thermalmedium through thedischarge line 33,-

occasioned by the pressure-relief operation of valve 32, the waterpressure and volume in the system may, on reduction in temperature, besubstandard. In such a circumstance, and also in the circumstance ofleak-age or other removal of water from the boiler, the pressurereducing valve 30 will permit an inflow of water into the boiler untilthe pressure in the heating system is equal to the pressure setting ofthe valve 30, such pressure being the normal for a particular tempera--ture condition. It will be understood, therefore, that the pressurereducing valve serves as a means for automatically maintaining apredetermined pressure and volume condition within the thermal system.If means other than the valve 30 are provided to maintain a desiredpressure at the source of water supply, the stated valve 30 may bedispensed with. However, as is common experience, the pressure of waterin the supply main is generally in excess of the safe pressure to whichthe conventional heating boiler may be exposed, and thus a pressurereducing 34, the inlet and outlet of which coil may be.

connected, as by piping 36 to a storage tank 33. A pipe 31 represents asupply line to the fixtures which are to utilize the hot water. Thecustomary water supply line is not shown.

Independent and familiar means, notshown, may be employed to control therate of combustion within the boiler l0, and thus maintain thetemperature of water therein within desired predetermined range.

In general, the heating system previously described is of a typefamiliar to those skilled in the art. The present invention, however,embodies means serving efliciently to absorb or dampen sound wavevibrations and/or other wave formations normally transmitted by thewaterfilled system to all parts of the residence or other "structureserved by the heating system. Additionally, means are provided wherebythermosyphonic circulation of water through the system may be positivelyprecluded or controlled. Preftion Serial No. 171,540, filed October28th, 1937 entitled Air cushion fitting for thermal systems.

Such absorbent cushion serves with equal facility during a status ofoperation of the system in which only the auxiliary system is in use,such circumstance contemplating a condition when it is neither desirablenor necessary that heated water be circulated to the radiators ll.serving the room or other enclosures.

The structure 40 embodying the cushioning means and therewith combinedflow valve may comprise a cast or otherwise fabricated fitting having agenerally s-shaped passage 4| therethrough, the configuration of thepassage being achieved by the oppositely disposed, spaced-apart baffles42 and 43, the termini of such baiiies having an appreciable overlap.Advantageously, the

structure 40 may be cast from brass or grey iron,

' thus the valve is in normally closed position. An

ear 52, preferably integral with the tongue 53 to which the valve disc50 is secured for the stated pivotal mounting, may be adapted tocooperate with an adjustment screw 54 to permit regulation of the degreeof closing of the valve disc 50, in any position from full closed, asindicated in Fig. 2, to full open. Screw 4 may pass through a suitabletapped lug 55; a compression nut 56 and suitable packing 51 serve toinsure the water tightness of the adjustment means.

As indicated in Fig. 2, the configuration of the fitting. 40 forms adome-like chamber 60 above the fluid-passage 4|, such chamber serving toentrap a volume of occluded air or gas. or steam or vapor driven offfrom the water in the heating system. The entrappedair in chamber 60serves very effectively to cushion the system against .the transmissionof shocks or vibrations because, as indicated by the line A-A in Fig. 2,representing the normal level of the surface of. the entrapped gaswithin the chamber 60 under usual operation conditions, the area of freesurface of the gas is ordinarily greater than the greatest area of theheating main 12. The area of the main I2 is at a maximum at the point'ofits connection with the boiler I0, and the structure 40 is installed inthe system at the boiler, as is indicated in Fig. 1. It will thus beseen that an air cushion of particularly great free surface isinterposed directlyin the path of water flow in the system.

The air cushion need not be of large colume, in order to functionefficiently. It is, however, desirable that the free surface of the aircushion be of large area, and that the stated free surface the mainthermal system, the air cushion 80 functions in its normal manner toabsorb shocks or vibrations arising within the boiler ll during theoperation of the auxiliary heating system, and

thus minimizes the transmittal of such vibration to'other parts of thesystem. Suchvibrations may be generated through the operation of therelief valve 32, the pressure reducing valve 30 or any of the otheraccessories to the heating system.

In initiating the operation of the system, air or other gas occluded inthe water or other thermal fluid is driven through the passage 4| ofstructure 40 and into the radiators I! or. associated pipingconnections, from which such gas may be released by the customary ventvalves Ila. The air may traverse the-passage 4| by the action of theposi-. tive water circulation generated by the circulator 23, thevelocity of water flow through-the system serving to carry entrapped airpast the barriers 42 and 43 of the structure 40 and'into the mains l2.

. Such movement of air or other gas into the units H andassociatedpiping continues until the position of the free'surface of air withinstructure 40 provides for a liquid passage between the stated airsurface and the top of barrier 42 adequate to permit the free flow offluid through the structure ,40 without further entrainment of air orgas. No further removal of air from the chamber 60 will occur.

When the fluid pressure in the system rises due to the increase intemperature of the water, a corresponding reduction in the volume of airwithin the chamber 60, and a corresponding reduction in the area of freesurface of the air occurs, due to the dome configuration of the airchamber 60. Such contraction will continue until the pressure throughoutthe entire system, including the pressure of gas within the chamber 60-attains the setting point of the relief valve 32, whereupon onincreasing temperature, the valve 32 will function to discharge adefinite volume of the thermal fluid through vent pipe 33, thuspreventing the creation of excess pressure conditions within the system.The volume and configuration of air chamber 60 are preferably such thatunder conditions of maximum pressure within the system permitted byrelief valve 32, the area of free surface ofthe entrapped gas is equalto or greater than the maximum diameter of main l2.

It will thus be seen, therefore, that in this invention, an adequatesound and shock absorbing cushion is maintainedat all times, the freesur-, face of the air cushion being equal to or greater than the area ofthe heating main.

On reduction of water temperature, and con sequent reduction of pressureof fluid within the system, an expansion of the air cushion will takeplace. the point of setting of pressure reducing valve 30, the statedvalve will function to admit water through the supply piping 26 to makeup the deficiency in the system. Accordingly, therefore,

the entire heating system is maintained in a state the thermostat 25functions to-closethe electrical circuit to the clrculator 24 if thetemperature condition surrounding the thermostat is subnormal. 'I'necirculator 24 will immediately function, and the resulting velocity headof water within the main 12 will exert suflicient pressure against valve50 to cause it to open, thereby permitting the circulation of heatedfluid through the heat exchange units il. Upon the attainment of thedesired temperature of air in the enclosure in which the thermostat islocated, the thermostat will function to break the electrical circuit,thus stopping the operation of the circulator 24.

The immediate reduction in the velocity head of water, will permit thevalve 50 to'close, precluding thermo-syphonic circulation of heatedwater to the heat exchange units IT. The heating sys- .tem is,accordingly, quickly responsive to thermostatic control, and quiet andsmooth in operation.

Should it be desirable that thermo-syphonic circulation in some degreebe permitted throughout the system, to the end that a sufficient fiowofheated water may reach heat exchange units having exposed locationsandthus prevent the possibility of. freezing of water within such heatexchangers, a manipulation of the adjustment screw 54 readily providesfor holding valve 50 open in any desired degree.

It will be observed that the auxiliary heating system is independentfrom the main heating system only inthat the auxiliary system mayfunction without the transmission of the heated water through the mainheating system to the heat exchangers". The function of the air cushionmeans, however, continues in full force and effect under all serviceconditions.

The circulation pump 23 may be dispensed with, in which circumstance thevalve 50 may be retained in full open position through the agency of theadjustment screw 60. Thermo-syphonic circulation through the system maybe precluded by permitting the valve 50 to assume its normal closedposition, or may be regulated in any degree by a suitable degree ofclosure of the stated valve'means.

Whereas I have described my invention by reference to specific formsthereof it will be understood that many changes and modifications may bemade without departing from the spirit of the invention.

I claim:

1. In a heating system employing the circulation of heated water througha closed piping system incorporating one or more heat exchange,

units, the combination of a heating boiler, and valve means forregulating or precluding thermo- 5 syphonic circulation of water throughthe system, said valve means including gas-entrapping meanscommunicating directly with said closed piping system and interposing aresilient gascushion directly in the path of flow of water 50 throughthe system, the stated gas-cushion having its free surface disposed inand serving to define a portion of the path of water circulation.

2. In a heating system employing the circulation of heated water througha closed piping sys- 55 tem incorporating one or more heat exchangeunits, the combination 'ofa heating boiler, and valve means forregulating or precluding thermo; syphonic circulation of water throughthe system, said valve means including gas-entrapping means nocommunicating directly with said closed piping system and interposing aresilient gas-cushion directly in the path of flow of water through thesystem, the stated gas-cushion having its free surface disposed in andserving to define a portion 65 of the path of water circulation, saidfree surface being at least equal to the area of the maximum pipe of thepiping system,

3. In a heating system employing the circulation'of heated water througha closed piping syst m incorporating one or more heat exchange nits, thecombination of a heating boiler with bombined flow-valve and air-cushionmeans, said last-mentioned means comprising a unitary structureembodying a normally closed, weighted valve and an air entrappingchamber disposed anteriorly thereof, said chamber being directlydisposed in and serving to define a portion of the path of water flowthrough said system and thereby serving to absorb shocks or water bornewave-formations.

4. In a heating system employing the circulation heated water through aclosed piping system incorporating one or more heat exchange units, thecombination of a heating boiler with combined flow-valve and air-cushionmeans, said last-mentioned means comprising a unitary structureembodying a normally closed, weighted valve and an air entrappingchamber disposed anteriorly thereof, said chamber being directlydisposed in and serving to define a portion of the path of water flowthrough said system and thereby serving to absorb shocks or water-bornewave-formations, said cushion having its free surface above and indirect contact with the water circulating through said closed pipingsystem.

5. In a heating system employing the circulation of heated water througha closed piping system incorporating one' or more heat exchange units,the combination of a heating boiler with gas-entrappiing meanscommunicating directly with said closed piping system and interposing aresilient gas-cushion directly in the path of flow of water through thesystem, the heated gasentrapping cushion having its free surface dis-.

posed in and serving to define a portion of the path of watercirculation, said free surface being at lease equal to the area of themaximum pipe of the piping system; said pressure-relief meanscooperating with said air cushioning means to provide an upper limit ofpressure within said air cushioning means, whereby the area of freesurface of said air cushion may be maintained at all times withinpredetermined limtis.

6. In a heating system employing the circulation of substantiallyincompressible, heated fluid, the combination with means for heatingsaid fluid, a closed piping system for effecting circulation of thefluid through the heating system, said piping system including oneoimore heatexchange devices, means for mechanically circulating suchfiuid through the system, temperature-sensitive means for controllingthe operation of such circulating means, and valve means disposed in thepiping system closely proximate the connection of the piping with theheating means and anterior to the connection of the said one or moreheat-exchange devices, said valve means being arranged to be moved toopen position during the stage of operation of said circulating means,of means having a'hollow interior for entrapping gas to cushion surgesof the heated fluid, said air-entrapping hollow interior communicatingdirectly with the interior of the piping and providing for contact ofthe free surface of the entrapped air with the fluid and serving todefine a portion of the path of flow of the fluid in the piping system,said free surface being disposed between said valve means and saidheating means, the area of said surface being at least equal to themaximum pipe area of the piping system during the normal stage ofoperation of the heating system.

EDWARD S. CORNELL, JR.

